Wire line jars



March 13, 1962 c w. COFFEE 3,024,854

WIRE LINE JARS Filed Dec. 2, 1958 FIG. 3

.z r, 7 F G I INVENTOR:

3,924,854 Patented Mar. 13, 1962 dice 3,024,854 WIRE LTNE JARS Charles W. Coffee, 1507 13th St, Lubbock, Tex. Filed Dec. 2, 1958, Ser. No. 777,644 9 Claims. (Cl. 175-299) This invention relates to recovering objects (fish) which are stuck within wells and more particularly to devices for imparting an upward jolt, impact, or jar to the fish.

An object of this invention is to provide a device for imparting upward jars or impacts to fish stuck within a well.

Another object is to provide such a device which may be operated by a single flexible line by which it is suspended.

Another object is to provide such a device wherein the amount of impact may be regulated by the operator.

Another object is to provide such a device that is completely mechanical in its operation and does not depend upon compressed fluids for actuation.

Another object is to provide such a device which makes use of an unregulated escapement as the means for retarding the hammer before striking the anvil.

Another object is to provide such a device wherein it may be reset for operation quickly and without employing excessive weight.

A further object is to provide such a device with a minimum of strain and shock upon the critical moving parts thereof.

A further object is to provide a device by which a steady upward force may be exerted on the fish at the time of impact.

Still further objects are to achieve the above with a device that is sturdy, compact, simple, and reliable, yet inexpensive and easy to manufacture.

The specific nature of the invention as well as other objects, uses, and advantages thereof will clearly appear from the following description and from the accompanying drawings in which:

FIG. 1 is an elevational view of a jar in accordance with this invention partially broken away.

FIG. 2 is a sectional view of the lower portion of the device shown in FIG. 1.

FIG. 3 is an elevational view of the escapement mechanism with the casing broken away as would be seen on line 33 of FIG. 2.

FIG. 4 is a cross sectional view taken on line 44 of FIG. 2.

FIG. 5 is a sectional view similar to FIG. 2 of the escapement mechanism shown with the hammer in an elevated position from that shown in FIG. 2.

The drawings illustrate one embodiment of this invention. The term fish is used to designate any object which may be stuck within a well.

The housing of the tool is tube which has at its upper end anvil 12. The bottom of the tube 10 has means 14 for attaching a grapple of any conventional type for connecting the tool to the fish to be removed from the well. Thus threads 14 are a means for attachment to an object stuck within a well. Within the tube there is the hammer 16 which together with an upper extending rod 13 has considerable weight. It is the weight of the hammer 16 and rod 18 striking against the anvil 12 that gives the jar or impact which breaks the fish loose.

Rod 20 depends from the hammer 16. At the bottom of the rod 20 there is a rack 22. Gear 26 is mounted on shaft 24 which extends diametrically across the tube. Gear 26 mates with the rack 22. Star wheel 28 is also mounted on the shaft 24 so that the star wheel rotates with the gear.

Pallet 30 is mounted in operative relationship with the star wheel so that the pallet 30 and star wheel 28 act as an escapement. As such unregulated escapemeuts are well known, they are not further described here. By unregulated escapement is meant an escapement which does not have an element regulated to oscillate at a set period, such as a pendulum or a spring biased balance wheel. Such unregulated escapemeuts do have a pallet that reverses its direction of movement during operation. However, the more force acting upon the star wheel the faster the escapement runs. The pallet is mounted on bell crank 32 which is pivoted about shaft 34 which parallels the shaft 24. Follower 36 on the other end of the bell crank acts in cam groove 38, which is attached to rack 22.

If the hammer is urged or pulled or stressed upward by means which will be described later, it will tend to move upward. The star wheel will rotate responsive to this upward movement, however the star wheel rotation will be retarded by the pallet 30. Therefore there will be a certain retardation in the upward movement of the hammer. This will give the operator of the equipment ample time to stretch the wire line by which the tool is suspended from the top of the well to whatever degree of tension needed to give the desired impact, i.e., if he desires to cause a relatively light blow to be struck, he may exert a 5000 pound pull upon the wire line which will cause the hammer to strike the anvil with a correspond ing impact. If a heavier blow is desired, the operator may exert a greater pull upon the wire line. Of course the line has a certain amount of elasticity to it, therefore a certain amount of time is required to reel in the necessary wire to exert the necessary tension in the tool below.

When the tension or force is exerted upon the hammer 16, it will move slowly upward, being retarded by the escapement.

The cam surface 38 is arranged so that after a certain length of time the bell crank will be rotated clockwise about shaft 34- to the position seen in FIG. 5. This clockwise rotation will cause the pallet to move out of engagement with the star wheel. When this occurs there will no longer be any retarding action upon the star wheel or gear 26 so that the hammer may travel freely to gain momentum so that it strikes the anvil 12 with considerable velocity and impact. By removing the pallet from the star wheel there is no excessive strain upon any of the teeth of the rack 22 or gear 26 as there would be if the gear were allowed to run off the rack with the pallet still engaged. However, after the pallet has disengaged, there is no longer any reason to rotate the gear train (including the star wheel 23); therefore, the teeth on rack 22 are discontinued on the lower end of the rack. This prevents shock on the gear train when the rack abruptly stops at impact.

After a blow or impact has been delivered by the means described, if the operator at the top of the well releases the tension on the wire line, the weight of the hammer and rod is will cause these two to move downward carrying with it rack 22. As may be seen from the drawings, on the downward stroke the bell crank will not follow the same path as it does upon the upward stroke of the rack. I.e., the follower 36 will follow a different path (right hand path 39) so that the pallet is out of engagement upon the downstroke. Specifically with the rack 22 moving upward and carrying the cam surface with it,

the follower 36 will strike a slanted portion 41 of the cam surface so as to force the follower 36 to the right causing the bell crank to rotate. Follower 36 will move into an extension of the right hand path which is aligned with the right hand path 39 below the slanted surface mentioned above. Upon the downward movement of the rack and the cam surface, the follower will remain in position so that continued downward movement of the rack will leave the follower in the right hand path primarily because of inertia. Continued downward movement of the rack will position the cam grooves 38 and follower 36 in the position as seen in FIG. 5. When the rack and cam surface reach the extreme bottom of the strokes, the upper slanting surface 43 of the cam groove will push the cam follower to the left as seen in FIG. 2 and rotate the bell crank 32 counterclockwise. Thereafter, upward movement of the rack will move the cam surface upward relative to the follower and the follower will remain in the left hand path as shown in FIG. 2. There is no retardation of the motion upon the downward stroke. The device may be quickly reset to deliver the next blow.

Although the device as described above is completely operative and useful, often it is desired to exert a steady pull upon the fish and at the same time deliver an impact to the fish. This can be achieved by attaching a tension spring 40 or other resilient member to the top of the rod 18. The top of the tension spring is attached to the wire line 42 by a block 44. A means 46 is integral to the anvil for limiting the upward travel of the line relative to the anvil. This takes the form of a bail extending upward from the anvil with cross member 47 at the top. The cross member has a hole through which the line 42 extends, however the hole is too small for the block 44 to pass through.

If the operator exerts a maximum force upon the wire line 42 it will be a force sufficient to extend the spring its entire length so that the block 44 rests under the cross member 47. A certain amount of force will be transmitted from the wire line through the means 46 and tube directly to the fish. However the spring 40 will still he urging the hammer upward until such time as the pallet falls away from the star wheel permitting the hammer 16 to deliver the impact.

A partition 48 is mounted in the tube 10 between the hammer 16 and the escapement mechanism. The shaft 20 extends through a hole at one edge of partition 48. Thus the partition 48 serves as a guide to prevent the rotation of the hammer 16 so that the rack 22 would no longer be engaged with the gear 26. Also the partition provides a means whereby the escapement mechanism may be filled with a lubricating oil if desired. Further it will be noted that there is a boss around the hole through which the shaft 20 extends. The chamber in which the hammer operates would be dry. However, if some fluids within the well were to leak into this chamber, they would be trapped in the area below the boss and therefore not pass on into the area containing the escapement mechanism.

It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction, materials, and arrangement within the scope of the invention as defined in the appended claims.

I claim:

1. A jar for jolting objects stuck within a Well comprising: a housing, an anvil at the upper end of the housing, means for attaching the housing to an object stuck within the well, a hammer within the housing below the anvil, a rack connected to said hammer, a star wheel mounted for rotation about a shaft, said shaft mounted in the housing, means interconnecting said rack and star wheel so that said star wheel is rotated by movement of said rack, and a pallet contacting the star wheel so that the movement of the rack is retarded by the escapement action of the star wheel and pallet.

2. The invention as defined in claim 1, wherein said pallet is mounted at one end of a bell crank, said bell crank being pivoted to the housing between its ends, the other end of said bell crank having a follower, a cam surface on said rack, said follower engaging said cam surface; so that as the hammer moves upward, at a predetermined point the cam surface rotates the bell crank moving the pallet away from the star wheel, permitting the hammer to move freely to gain momentum to strike the anvil.

3. The invention defined in claim 1 with the addition of a tension spring connected to the top of the hammer, a wire line connected to the top of the tension spring, and a bail extending upward from the anvil, said line passing through a hole in the bail, a block at the connection of the wire line to the tension spring so that the wire line is restricted in the amount of movement it may have away from the anvil by the block contacting the bail.

4. A jar for jolting objects stuck within a well comprising: an anvil, means for attaching the anvil to an object stuck within the well, a hammer below the anvil, means connected to the hammer for retarding the movement of hammer toward the anvil, a tension spring attached to the top of the hammer, a flexible line attached by a block to the top of the spring, and a bail extending upward from the anvil, the bail having a hole in the top thereof through which passes the line, the block being larger than the hole so that the line is limited in its movement away from the anvil.

5. In a jar having a housing, an anvil at the upper end of the housing, means for attaching the housing to an object stuck within a well, a hammer within the housing below the anvil, and means for applying upward stress to said hammer so that it tends to strike the anvil, the improvement comprising:

(a) a two element escapement,

(b) one element connected to the hammer,

(c) the other element connected to the housing,

(d) the elements in contact with each other,

(e) the escapement being a portion of means for retarding the movement of the hammer toward the anvil.

6. The invention as defined in claim 5 wherein said means for applying upward stress to said hammer includes (f) a tension spring,

(g) said spring attached at its lower end to the hammer,

(h) a block,

(i) said spring attached at its upper end to the block,

and

(j) means for limiting the travel of the block relative to the anvil.

7. In a jar having a housing, an anvil at the upper end of the housing, means for attaching the housing to an object stuck within a well, a hammer within the housing below the anvil, and means for applying upward stress to said hammer so that it tends to strike the anvil, the improvement comprising:

(a) a star wheel mounted for rotation within said housing,

(b) means for rotating the star wheel responsive to movement of the hammer toward the anvil, and

(c) a pallet mounted within the housing in operative relationshi to said star wheel.

8. The invention as defined in claim 7 with the addition of means for moving the pallet and the star wheel out of operative relationship so that the movement of the hammer toward the anvil is not retarded.

9. In a jar having a housing, means for attaching the housing to an object stuck with a well, an anvil at the top of the housing, a hammer within the housing below said anvil, and means interconnecting said hammer and housing for retarding the movement of the hammer toward the anvil; the improvement comprising:

(a) a resilient element attached to the top of the hammer,

(b) a block attached to the top of the resilient element, and

(0) means for limiting the travel of the block relative to the anvil.

References Cited in the file of this patent UNITED STATES PATENTS Edwards Mar. 27, 1923 McCullough Apr. 5, 1932 McCullough Mar. 31, 1936 Chapman July 29, 1941 Beck June 28, 1949 Barnes Sept. 11, 1956 

